import type { RillConfigFile } from '@rcrsr/rill-config';
import { ConfigNotFoundError } from '@rcrsr/rill-config';
export { ConfigNotFoundError };
export interface ConfigSnapshot {
    readonly path: string;
    readonly rawText: string;
    readonly parsed: RillConfigFile;
}
/**
 * Thrown when writing rill-config.json to disk fails.
 * Wraps the underlying I/O error message.
 */
export declare class ConfigWriteError extends Error {
    constructor(configPath: string, cause: unknown);
}
/**
 * Reads <projectDir>/rill-config.json and returns a snapshot of the raw text
 * and parsed structure.
 *
 * @throws {ConfigNotFoundError} when the file does not exist (ENOENT).
 */
export declare function readConfigSnapshot(projectDir: string): Promise<ConfigSnapshot>;
/**
 * Applies a mount add/overwrite/remove edit to the config file on disk, then
 * validates the result via loadProject. On validation failure the original
 * rawText is written back byte-for-byte and the original error is re-thrown.
 *
 * @throws {ConfigWriteError} when the disk write itself fails (EC-30).
 * @throws {MountValidationError | NamespaceCollisionError} on validation
 *   failure after rollback (EC-29).
 */
export declare function applyMountEdit(snapshot: ConfigSnapshot, edit: {
    kind: 'add' | 'overwrite' | 'remove';
    mount: string;
    value?: string;
}, prefix: string, options?: {
    skipValidation?: boolean;
}): Promise<void>;
/**
 * Returns true when the snapshot contains a mount entry for the given path.
 */
export declare function hasMount(snapshot: ConfigSnapshot, mount: string): boolean;